Electronically scanned antennas, normally flat, are ill-suited to circular panoramic applications, unless they are equipped with a mechanical rotating device. Another solution involves juxtaposing several flat antenna panels to cover all 360°. These solutions are complex or costly to implement. For these reasons in particular, they are ill-suited, or even not at all suited, to applications such as, for example, marine telecommunication antennas installed at the top of masts.
One aim of the invention is in particular to make it possible to simply produce a cylindrical antenna. To this end, the subject of the invention is a cylindrical electronically scanned antenna comprising at least:                a set of radiating guides arranged in cylinder form, producing the antenna beam;        an array of 3 dB couplers in waveguide form, the inputs of which are lit by a set of microwave feeds, the output of a coupler being coupled to the input of a radiating guide;        an array of pairs of phase-shifting cells, each coupled to a 3 dB coupler, an incoming wave from the microwave feeds being phase-shifted by a controllable phase shift Δφ, the angular offset of the antenna beam being dependent on this phase shift.        
Advantageously, the microwave feeds are arranged on a cylindrical circumference inside the cylinder formed by the set of radiating guides so that each feed lights a part of the array of couplers, the microwave feeds being activated in turn.
The microwave feeds are, for example, horns linked to a microwave line switching device, each horn supplied by a line.
Advantageously, the switching device is, for example, an SP8T-type device. This switch can be MEMS-based.
In one embodiment, the incoming wave entering the input of a coupler is split into two waves, these two waves each being reflected on a phase-shifting cell with identical phases and being recombined into a resultant phase-shifted wave leaving via the output of the coupler juxtaposed to the input.
The phase-shifting cells comprise, for example, diodes, the applied phase shift being dependent on the state of the diodes.
In another embodiment, the phase-shifting cells comprise, for example, tunable MEMS, the applied phase shift being dependent on the impedance of the MEMS, this impedance being controllable.
The microwave feeds are, for example, arranged on an internal cylindrical wall, the feeds lighting the couplers in the available space between the internal wall and the radiating guides.
The radiating guides are, for example, slotted guides.